Fuse construction



Feb. 13, 194@. C) SCHULTZ 2,189,764

FUSE CONSTRUCTION I Filed Aug. 31, 1956 3 Sheets-Sheet l I N VENT OR.

W/ZZ/AW Q Sam/172 fig F %ORNEY.

Feb. 13, 1940. w. o. SCHULTZ 2,189,764

FUSE CONSTRUCTION Filed Aug. 51, 1936 3 SheetsSheet 2 I INVENTOR. W/LZ/AM 0 Sam/U2 ATTORNEY.

Feb. 13, 1940. w. o. SCHULTZ 2,189,764

FUSE CONSTRUCTION Filed Aug. 31, 1936 3 Shegts-Sheet 3 INVENTOR. W/u/M 0. Sax/01 rz RNEY.

Patented Feb. 13, 1940 UNITED STATES FUSE CONSTRUCTION William 0. Schultz, South Milwaukee, Wis., assignor to Line Material Company, South Milwaukee, Wia, a corporation of Delaware Application August31, 1936, Serial No. 98,848

16 Claim.

This invention relates to a fuse construction and is particularly directed to a fuse construction associated with a transformer or other electrical device.

This invention is intended to provide a fuse construction which is particularly useful on a single bushing transformer which is now quite common for rural service. These transformers are made up with only one primary bushing, the other side of the primary winding being solidly grounded to the transformer case.

Objects of this invention are to provide a fuse construction in which the fuse structure is carried by or supported from the transformer bushing, in which only moderate stresses are imposed on the bushing and the bushing is thus relieved of undue strains, in which the fuse is so mounted that the expelled gases and metallic vapors are directed away from the casing particularly as the fuse moves to inoperative position, and in which an expulsion type of drop-out fuse is provided.

Further objects are to provide a construction in which an expulsion type of'drop-out fuse is readily applied to or removed from any of the usual types of single bushing transformers, in which provision is made for detachably locking the base of the fuse construction to the conducting stud or member carried by the transformer bushing so that the base and stud jointly form a portion'of the electrical circuit to the transformer.

Further objects are to provide a fuse construction in which the fuse is so mounted that it is biased by gravity to drop to inoperative position when released by the fuse link, in which no springsare employed, and in which a very simple and cheap construction is obtained.

Further objects are to provide a construction in which the drop-out fuse is so mounted and so constructed that it may be manually moved to open position while the fuse link is intact, and in which the fuse tube may be operated by a fuse stick without requiring the operator or lineman to get above the transformer but allowing him to operate the fuse while the lineman is supported on a pole at a considerable distance below the fuse tube, thereby avoiding danger of the lineman coming in contact with transformer lead wires and overhead feeder wires, and thus allowing the lineman to operate the fuse tube without having to assume any abnormal positions.

Further objects are to provide a fuse construction for transformers in which surge protection is provided so that when the fuse blows, the transformer is nevertheless protected against surges as an arcing gap is provided independently of the position of the fuse tube.

The different manufacturers of single bushing transformers position the arcing tip, which is carried by the casing of the transformer, at dif- 5 ferent distances and different positions with respect to the bushing.

This invention is designed to provide a fuse construction in which an adjustable arcing horn is provided, which has both motion of translation 10 and motion of rotation, that is to say, in which the arcing horn may be pulled out or pushed back with reference to its support or may be rocked about a pivot point so as to accurately align the arcing horn with the arcing tip.

Embodiments of the invention are shown in the accompanying drawings, in which:

Figure 1 is a side elevation with parts broken away and in section showing the fuse construction applied to a single bushing transformer, a go fragment of the transformer casing being shown.

Figure 2 is a similar view taken at right angles to Figure 1.

Figure 3 is a plan view of the fuse structure.

Figure 4 is a sectional view on the line 4-4 of 25 Figure 2.

Figure 5 is a plan view showing a further type of arcing horn.

Referring to the drawings, it will be seen that the metallic transformer casing has been indicated by the reference character i and the insulating bushing by the reference character 2. The transformer stud or terminal 4 is threaded and projects through the bushing 2 and receives a cap nut l which is provided with an integral stud 3. The cap nut I and its integral stud 3, therefore, constitute the terminal portion of the transformer. The stud 3 is thus rigid with the bushing. The casing I is also provided with an arcing tip 5 which may consist of an upwardly 40 projecting rod carried by the casing.

The fuse construction includes a metal base portion 6 which is socketed and fits over the stud 3 and is locked to the stud by means of a set screw 1, see Figure 4. Preferably the socket has 45 a relatively tapered aperture indicated at 8, as in Figure 4, to allow the socket to take difierent sizes of studs and to wedge the stud in place when the set screw 1 is tightened, to thus provide a rigid supporting means for the fuse construc- 60 tion.

The base is provided with a laterally extending arm 9 integral therewith and provided with a pivot portion [0 headed as indicated at II in Figure 3. Them 9 isalso provided withali ber is provided with an arm I5 that projects laterally therefrom and is equipped with a. sleet hood 16 provided with divergent side portions,

as shown in Figure 3, which serve to assist in guiding the upper end of the fuse tube into place when it is being rocked to closed position.

The terminal member I5 is also provided with a tying eye l1. Within the sleet hood a contact member l8 in the form of a spring arm is provided and is secured as indicated at I9 interiorly of the sleet hood. This contact member or arm is apertured and is provided with an upwardly turned cam portion 20 and with an outwardly slanted guiding lip 2|.

The contact member 18 projects downwardly below the inner end of the sleet hood and receives a connector 22 by means of which the line wire 23 may be secured thereto. The line wire thus is directly attached to the upper contact. If the distance between the point of support of the line wire and the fuse is great, the line wire may be tied to the tying member ll, as shown in Figure 1. Otherwise it may extend directly to the upper contact member.

The fuse is of the drop-out expulsion type and comprises a fuse tube 24 having an upper contact or terminal 25 which includes a clamping cap 26 provided with an upwardly extending projection 21 normally fitting within the recess of the contact member l8 and beyond the lip 20, as shown in Figure 1. This upper cap clamps the button of the fuse link to the upper terminal of the fuse. The member 25 is preferably provided with a pull ring 28 integral therewith and projecting outwardly therefrom. The fuse link may comprise the fusible portion 29 and the leader 30, the leader projecting outwardly through the lower open end of the fuse tube.

Mechanism in the form of a bell crank lever 3| is provided and is pivotally joined to the fuse tube and to the support. The fuse tube is provided with a collar 32 which has rearwardly projecting ears 33 and the lever 3| is pivotally joined to the ears 33 by means of the pin, 34.

The lever is provided with a pair of hooked arms 35 which hook over the pivot Ill and thus motion by the support I2.

allow the fuse to be detached from the pivot during refusing after the fuse has rocked downwardly. The lever 3| is limited in its rocking The lever 31 is provided with a portion or arm 36 provided with a thumb nut 31 by means of which the leader 30 of the fuse link may be locked to thelever, so that the lever is restrained from releasing motion by the fuse link. It is clear that when the fuse link blows, the lever M will be released and will rock about the pivot portion i0 and thus lower the upper end of the fuse from the upper latch or contact iii, thus disengaging the upper end of, the fuse tube and allowing it to rock into the dotted line position. Preferably a pin 38 is carried by the base portion 6 for limiting the downward motion of the fuse tube.

It will be seen that the open end of the fuse tube rocks away from the casing of the transformer and away from the bushing and thus dirests the discharging gases and metallic vapors away from the casing.

Further than this, it is apparent that the pivot point is mounted closely adjacent the bushing and that the pivot point and upper contact or latch are mounted on opposite sides of a plane passing through the axis of the bushing. Consequently when the fuse tube is pulled downwardly, as by means of a fuse stick or switch stick inserted in the eyelet 28, there is no great strain placed on the insulator or bushing.

Further than this, it is apparent that the operator can reach the fuse tube with a switch stick while the operator is below the transformer and may pull the device open by a substantially downwardly directed pull, thus avoiding the necessity of the operator climbing above the transformer into the relatively dangerous zone of feeder wires, etc., and also allowing the operator to open the device without requiring him to assume any abnormal or inconvenient positions.

The fuse tube is biased by gravity towards inoperative position and no springs are required for the operation of the device.

It is to be noted particularly from Figures 2 and 3, that the upper terminal member I4 is provided with an arm 39 projecting laterally therefrom and carrying a locking bolt 40. An arcing horn 4| is provided and is preferably slotted, as indicated at 4-2, to receive the locking bolt 40. This arcing horn has a downwardly extending portion 43, see. Figure 2, which is aligned with the arcing tip 5. It is clear that the arcinghom may be moved in or out or may be rocked about the locking bolt 40 so as to accurately align the arcing horn with the arcing tip. It is obvious that the arcing horn may take other forms. For-example, it may be of a rod construction, as indicated at 44, and .may be provided with a rearwardly bent portion 45 to provide the slot 46.

It will be seen that the device is very simple in construction, that it is cheap to make, that it will fit many different types of transformers.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. In a circuit interrupter, a fuse structure, an insulating bushing, means supporting said fuse structure from said bushing, said fuse structure including a tube having an open lower end and movable from operative to inoperative position, a fuse link in said fuse tube, and restraining means controlled by said fuse link normally holding said fuse tube in operative position and releasing said fuse tube for motion towards inoperative position when said fuse link is ruptured, the open end of said fuse tube moving away from said bushing when said fuse link is ruptured, whereby the discharge from the open end of said fuse tube is directed away from said bushing.

2. In a circuit interrupter, a fuse structure, an insulating bushing, means supporting said fuse structure from said bushing, said fuse structure including a tube having .an open end and movable from operative to inoperative position, a fuse link in said fuse tube, said fuse tube being biased by gravity towards inoperative position, and restraining means controlled by said fuse link normally holding said fuse tube in operative position and releasing said fuse tu e for motion towards inoperative position when said fuse link is ruptured, the open end of said fuse tube moving away from said bushing whet said fuse link is ruptured, whereby the discharge from the open end of said fuse tube is directed away from said bushing.

3. In a circuit interrupter, an insulating bushing, a drop-out fuse structure supported from said bushing and including a pivotally mounted fuse tube movable from operative to inoperative position, mechanism normally holding said fuse tube in operative position and releasing said tube when said mechanism operates, and a fuse link restraining said mechanism from releasing operation, said fuse tube being biased by gravity towards inoperative position.

4. In a circuit interrupter, an insulating bushing, anchor means carried by said bushing, a fuse structure including a base portion detachably secured to said anchor means and forming with said anchor means a part of an electrical circuit, a fuse tube movably supported from said base portion and movable from operative to inoperative position, and a fuse link normally re,- straining said tube against motion, said fuse being manually movable from operative to inoperative position by a substantially downwardly directed pull. I

5. In a circuit interrupter, an insulating bushing, anchor means carried by said bushing, a drop-out fuse structure including a base portion detachably secured to said anchor means and forming with said anchor means a part of an electrical circuit, a fuse tube pivotally supported from said base portion, an .upper latch means for said fuse tube, and a fuse link within said fuse tube normally restraining said fuse tube againstpivotal motion, said fuse tube when released by said fuse link moving from operative position to inoperative position away from said upper latch means, said fuse tube being releasable from said upper latch means by a substantially downwardly directed pull while said fuse" link is intact.

6. In a circuit interrupter, an insulating bushing, anchor means carried by said bushing, a drop-out fuse structure including a base portion detachably secured to said anchor means and forming with said anchor means a part of an electrical circuit, a fuse tube pivotally supp r ed from said base portion, an upper latch means.

for said fuse tube, said fuse tube slanting downwardly from said upper latch means, whereby said fuse tube-tends to drop downwardly when released from said upper latch means, and a fuse link within said fuse tube normally, re-

straining said fuse tubeagainst pivotal motion, said fuse tube when released by said fuse link moving from operative position to inoperative position away from said upper latch means, said fuse tube being releasable from said upper latch means by a substantially. downwardly directed pull while said fuse 'link is intact.

'7. In a circuit interrupter, aninsulating bushing, anchor means rigidly carried by said bushing, a fuse structure including a base portion detachably locked to said anchor means for supporting said fuse structure and forming with said anchor means a part of an electrical circuit, said base portion having a pivot portion located adjacent said bushing, a fuse tube pivotally supported from said pivot portion and normally projecting upwardly therefrom, an upper latch means for said fuse tube, said fuse tube being biased towards downward rocking motion away from said upper latch means, and a fuse link norinally restraining said fuse tube against motion.

8. In a circuit interrupter, an insulating bushing, anchor means rigidly carried by said bushing, a fuse structure including a base portion detachably locked to said anchor means for supporting said fuse structure and forming with said anchor means a part of an electrical circuit, said base portion having a pivot portion located adjacent said bushing, a fuse tube pivotally supported from said pivot portion and normally projecting upwardly therefrom, an upper latch means for said fuse tube, said fuse tube being biased towards downward rocking motion away from said upper latch means, and a fuse link normally restraining said fuse tube against motion, said pivot portion and said latch means being located on opposite sides of a plane passing through the axis of said bushing.

9. In a circuit interrupter, an insulating bushing, a fuse structure including a base and an upper contact, a fuse tube movably supported from said base and biased towards motion downwardly away from said upper contact, a fuse link within said fuse tube normally restraining said fuse tube against motion, and a support carried by said insulating bushing, said base and said support holding said fuse tube above the top of said insulating bushing, said fuse tube being manually movable away from said upper contact by a substantially downward pull and being reachable with a fuse stick passed upwardly.

10. In an apparatus of the class described, an electrical device provided with a metal casing, said casing having an arcing tip, an insulating bushing carried by said casing, a fuse structure for protecting said. electrical device supported from said bushing and having a base locked with respect to said bushing, a fuse tube movably supported from said base and biased towards motion from operative to inoperative position, an insulator carried by said base, a contact carried by said insulator, a fuse link normally electrically.

connecting said contact and said base and restraining said fuse tube against motion, and an arcing horn adjustably supported from said in-' sulator and connected to said contact.

11. In an apparatus of the class described, an electrical device provided with a metal casing,

'said casing having an arcing tip, an'insulating bushing carried by said casing, a fuse structure sulator and connected to said contact, said arcing horn having both translatory and rocking motion, whereby said arcing horn may be aligned with said arcing tip.

12. In a circuit interrupter, an insulating bushing, a fuse structure including a base supported from said bushing, said base having a pivot portion, a drop-out fuse tube, an upper contact, a lever pivoted to said fuse tube and said pivot portion and normally holding said fuse tube in engagement with said upper contact and adapted to release said fuse tube, said fuse tube being biased towards downward motion away from said upper contact, and a fuse link normally holding said lever against releasing motion.

13. In a circuit interrupter, a bushing, anchor means rigidly carried by said bushing, a fuse structure including a base portion detachably locked to said anchor means for supporting said fuse structure and forming with said anchor means a part of an electrical circuit, said base portion having a pivot portion located adjacent said bushing, a fuse tube pivotally supported from said pivot portion and normally projecting upwardly therefrom, and an upper latch means for said fuse tube, said pivot portion and said latch means being located on opposite sides of a plane passing through the axis of said bushing.

14. In anapparatus of the class described, an electrical device having a casing provided with a top portion and side walls, a fuse structure for protecting said electrical device and including a base and an upper contact. a fuse tube movably supported from said base, and a support carried by and insulated from said casing, said base and said support holding said fuse tube above the top of said casing and above and adjacent a side wall of said casing, said fuse tube being manually movable away from said upper contact and being reachable with a fuse stick passed upwardly adiacent a side wall of said casing.

15. In an apparatus of the class described, an\ electrical device having a casing provided with a top portion and side walls, a fuse structure for protecting said electrical device and including a base and an upper contact, a fuse tube movably supported from said base, and a support carried by and insulated from said casing, said base and said support holding said fuse tube above the top of said casing and above and adjacent a side wall of said casing, said fuse tube being manually movable away from said upper contact by a substantially downward pull and being reachable with a fuse stick passed upwardly adjacent a side wall of said casing.

16. In an apparatus of the class described, an electrical device provided with a metal casing,

said casing having an arcing tip, an insulating with said arcing tip.

WILLIAM C. SCHULTZ. 

